Up to now, a high-pressure pump has been known, in which a discharge valve and a relief valve are integrated with each other in a discharge passage through which a fuel pressurized in a pressurizing chamber flows. For example, in a high-pressure pump disclosed in Patent Literature 1, a spherical valve body is used as a valve body of the relief valve.
The high-pressure pump of Patent Literature 1 includes a holder that holds the valve body of the relief valve and an urging member that urges the valve body toward a valve seat through the holder. In this case, the movement of the valve body and the holder is not guided by another member, and can move relatively freely in a space between the pressurizing chamber and the valve seat. The fuel discharged from the pressurizing chamber of the high-pressure pump flows around the valve body and the holder to be discharged to the outside of the high-pressure pump. For that reason, the valve body and the holder may move or vibrate due to a flow of the fuel. If the valve body moves or vibrates in a state where the valve body is in contact with the valve seat, the valve seat or the valve body may be worn. If the valve seat or the valve body wears, a valve opening pressure of the relief valve may change over time.
Further, in the high-pressure pump of Patent Literature 1, since the valve body and the holder are formed separately from each other, there is a possibility that the valve body and the holder move relative to each other and the position of the valve body becomes unstable. As a result, wear of the valve seat or the valve body may be accelerated.